What is the order of p K_b for the following molecules in an aqueous medium?

Step-by-step solution

The basicity of an amine is inversely proportional to its p K_b value. A stronger base has a lower p K_b . 1. Molecule P (Benzylamine): It is an aliphatic amine. The lone pair of electrons on the nitrogen atom is localized and not involved in resonance with the benzene ring. Therefore, it is the strongest base among the given compounds and has the lowest p K_b . 2. Molecules Q, R, and S: These are aromatic amines where the nitrogen atom is directly attached to the benzene ring. The lone pair on nitrogen is delocali